A conductive film represented by an indium tin oxide (ITO) film is being used in various applications, for example, an electrode for a display device such as a plasma display panel (PDP) or a liquid crystal display (LCD), or an organic light emitting diode (OLED), and an electrode for a touch panel.
The conductive film may be manufactured by forming a conductive layer like ITO on one or both sides of a glass substrate or plastic film by a method such as deposition and the like.
In order to crystallize the conductive layer such as ITO in the manufacturing of the conductive film, a thermal treatment may be performed at a high temperature. Particularly, when the conductive layer is formed on a plastic film, and the thermal treatment is performed at a high temperature, due to the influence of a low molecular weight component such as an oligomer existing in the plastic film, bubbles may be generated in the conductive film, and such bubbles become a cause of degrading an optical property of the conductive film such as transparency. Particularly, when the conductive layers are formed on both sides of the film, they serve as a barrier to the bubbles, and therefore it is more difficult to remove the bubbles generated therein.